Hadith 21:45
Sahih (Darussalam)
It was narrated from 'Amr bin Shu'aib, from his father, from his grandfather, that the Messenger of Allah (ﷺ) said:
“A Muslim should not be killed in retaliation for the murder of a disbeliever.”
حَدَّثَنَا هِشَامُ بْنُ عَمَّارٍ، حَدَّثَنَا حَاتِمُ بْنُ إِسْمَاعِيلَ، حَدَّثَنَا عَبْدُ الرَّحْمَنِ بْنُ عَيَّاشٍ، عَنْ عَمْرِو بْنِ شُعَيْبٍ، عَنْ أَبِيهِ، عَنْ جَدِّهِ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " لاَ يُقْتَلُ مُسْلِمٌ بِكَافِرٍ "
Original Reference: Sunan Ibn Majah 2659